Process of obtaining lubricating oils from the hydrocracking of asphaltic hydrocarbon oils



3,240,696 CRACKING maord; @com 00E. ooo oom@ ooo@ com@ @oom @emv OCS.comm @oom @oww @com oo@ co9 oom AI 3201)/ .I KIQ/bilig( 1 Age/2f R. R.HALlK ET AL Filed Feb. 17, 1965 March 15, 1966 PROCESS OF OBTAININGLUBRICATING OILS FROM THE HYDRO OF ASPHALTIC HYDROCARBON OILS HSGWONNOILVZI'IVHMEIN United States Patent O PROCESS F OBTAlNING LUBRICATINGOILS FRM THE HYDROCRACKING 0F ASPHALTIC HYDRQCARBON GILS Raymond R.Halilt, Pitman Borough, Gloucester County, Henry R. Ireland, WestDeptford Township, Gloucester County, and Michael T. Smilski, MantuaTownship, Gloucester County, NJ., assgnors to Socony Mobil (lil Company,Inc., `a corporation of New York Filed Feb. 17, 1965, Ser. No. 433,35521 Claims. (Cl. 208-111) This application is a continuation-in-part ofapplication Ser. No. 159,340, led December 14, 1961, now abandoned, andapplication Ser. No. 237,163, filed November 13, 1962, now abandoned.

This invention relates to the production of improved lubricating oils.In one aspect, this invention relates to a method for preparing improvedlubricating oils suitable for use in engines, turbines and as automatictransmission iluid base stocks. In other aspects, this invention relatesto improved lubricating oils composed of the combination of a mixture ofspecific hydrocracked hydrocarbons and at least one lubricating oiladditive suitable for enhancing the properties of said hydrocrackedhydrocarbons to provide improved engine oils, turbine oils and automatictransmission fluids.

The desirable characteristics of satisfactory lubricating oils andspecific types of lubricating oils are known in the art. For instance, asatisfactory turbine oil should possess properties such as a high ashtest, a low viscosity, the ability to maintain its body and efiiciencyunder high temperatures, low moisture-absorptive capacity, oxidationstability and the like. Of the above-identified properties, theoxidation stability of a turbine oil is of extreme importance.Satisfactory automatic transmission fluid base oils should possess notonly most of the properties described above for turbine oils but inaddition, a low wax content and a high viscosity index so as to providelubrication over a wide temperature range. To provide lubricating oilswhich can be used for specific purposes and have acceptable physicalcharacteristics, the rening processes, which are known, generallyrequire a careful selection of the crude base stock, which may involve apretreatment step, and an expensive combination of refining steps suchas acid treatment, solvent refining, and the like to produce desirablelubricating oils under exacting and careful conditions. Although theseprocedures provide lubricating oils which can be satisfactorily used,these known processes are expensive, time consuming, and the yields ofthe lubricating oil product are generally low -since the impurities mustbe removed from the hydrocarbon charge stocks in the refining operation.It would be highly desirable to utilize a refining process which uses aminimum number of refining steps, converts impurities which aregenerally removed and obtain improved lubricating oils in higher yieldsover the known processes. It is the purpose of this invention to providethese improvements.

Accordingly, one or more of the following objects will be achieved bythe practice of the invention. It is an object of this invention toprovide an economical and commercially feasible process to produceimproved lubricating oils in high yields. It is a further object of thisinvention to provide a process wherein any type of asphaltcontaininghydrocarbon boiling above about 650 F. is hydrocracked to provideimproved lubricating oils in high yields. It is another object of theinvention to provide improved turbine oils which have superiorcharacteristics of improved oxidation resistance, improved durability,and possess other satisfactory properties required of acceptable turbineoils. An additional object of this invention is to provide improvedautomatic transmission iluid 355,240,695 Patented Mar. l5, i966 basestocks which have superior characteristics of improved oxidationresistance, improved shear stability, high viscosity indices and possessother satisfactory properties of acceptable automatic transmission iluidbase stocks. It is also an object of the invention to provide improvedlubricating oils composed of the combination of a mixture of specifichydrocracked hydrocarbons and at least one lubricating oil additivesuitable for enhancingl the properties of turbine oils, automatictransmission lluids and engine oils. It is a further object of thisinvention to provide a process wherein any type of asphalt-containinghydrocarbon boiling above 650 F. is hydrocracked and subsequentlysubjected to a percolating process over adsorbent materials to produceimproved oxidation resistant turbine oils. Numerous other objects willbecome apparent to those skilled in the art from a consideration of thedisclosure and appended claims.

In accordance with the present invention, improved lubricating oil-ssuch as engine oils, turbine oils, and automatic transmission lluid basestocks are produced by the treatment of an asphalt-containing petroleumhydrocarbon oil having a boiling point in excess of about 650 F. withhydrogen in the presence of a catalyst having hydrogenation and crackingproperties utilizing conventional hydrocracking conditions andseparating the lubricating oils from the hydrocracked product. Thestarting material which can be utilized in the process of this inventioncan be any asphalt-containing petroleum hydrocarbon boiling in excess of650 F. These petroleum hydrocarbons can be obtained by vacuumdistillation or like distillation of asphalt-containing crude oils, suchas, Mid-Continent, North African, Gulf Coast, West Texas, Kuwait amongothers. For purposes of this invention in producing lubricating oilssuch as turbine oils, it is essential that the hydrocarbon charge stockused in the hydrocracking process contain asphalt in amounts rangingfrom about 2 to about 70 volume percent preferably in the range fromabout 5 to about 40 volume percent of the charge stock. In producingautomatic transmission fluid base stocks, it is essential that thehydrocarbon charge stock used contain asphalt in amounts ranging froma-bout 2 to about 50 volume percent, preferably in the range from about2 to about 40 volume percent of the charge stock. The term asphalt asused herein is defined as the amount of asphalt tar which can be removedfrom the asphaltcontaining hydrocarbon charge stock by a propanedeasphalting procedure. It is an additional requirement of the petroleumhydrocarbon charge stock that this material is sufficiently iluid sothat is will llow and has the ability to be pumped. If the startingmaterial is not suiliciently fluid, a hydrocarbon diluent can be addedso as to provide the desired flowable viscosity.

In a particular aspect of the present invention wherein turbine oilshaving good oxidation stability are produced, an asphalt-containingpetroleum hydrocarbon oil having a boiling point in excess of about 650F. and containing asphalt in an amount in the range of from about 2 toabout 70 volume percent is hydrocracked in the manner described below.The turbine oil i-s separated from the hydrocracked product and ispercolated over an adsorbent material such as activated clay andactivated charcoal including bauxite, porocel, fullers earth and thelike.

The reaction conditions necessary in the hydrocracking process for theproduction of the improved lubricating oils of this invention include atemperature range from about 700 F. to about 870 F., preferably in therange from about 725 F. to about 850 F. The pressures which are employedinclude those ranging from about 1700 pounds per square inch gauge toabout 4000 pounds per square inch gauge, preferably in the range fromabout 2000 to about 3500 pounds per square inch gauge. The liquid hourlyspace velocity which can -be used ranges from about 0.1 to about 2.0,preferably in the range from about 0.2 to about 1.0. The hydrocrackingreaction conditions of this process to produce improved turbine oils aremaintained so as to provide a conversion in the range from about toabout 70 volume percent preferably in the range from about to about 45volume percent of the asphalt-containing hydrocarbon. The hydrocrackingreaction conditions required to produce autom-atie transmission fluidbase stocks are maintained so as to provide a conversion in the rangefrom about to about 70 volume percent preferably in the range from aboutto about volume percent of the asphalt-containing petroleum hydrocarbon.The term conversion las referred to herein is a generic term for theamount of products boiling below 650 F. obtained in the hydrocrackingprocess. The conversion is expressed in terms of volume percent `anddetermined as follows: 100-material in the product boiling about 650 F.expressed as volume percent of charge. It is a requirement of thisprocess to utilize pressures in excess of 1700 pounds per square inchgauge in order to provide satisfactory percolated turbine oils havingviscosity indices of -at least about 100.

Although the above-described hydrocracking process provides an adequateonce-through method to obtain the improved lubricating oils of thisinvention, a modification to this process will provide additionalimprovements. The presence of asphalt in the hydrocarbon charge stocktends to increase the aging properties of the catalyst utilized andrequires frequent regeneration. It has been discovered that recycle of aspecific product fraction of the hydrocracked hydrocarbon, i.e., thehydrocracked product boiling in the range from about 400 to about 700 F.does not only decrease aging of the catalyst and extend the operationtime before regeneration is required but this process also produces alubricating oil which is more viscous at the same conversion level thanthe once-through operation and produces a higher viscosity index oilproduct at the same viscosity level which would be a higher conversionlevel. The volumetric ratio of the recycle stock fraction obtained fromthe hydrocracked product to the hydrocarbon charge stock suitable toprovide the improved process ranges from 0.1:1 respectively, to about10:1 respectively, preferably in the range from about 1:-1 respectively,to about 5:1 respectively.

The catalyst employed in the process of this invention can include anytype of catalyst having hydrogenation and cracking properties. Suchcatalysts are known in the art, for instance, these catalysts caninclude oxides and suliides of any metal of Group VI lefthand column ofthe Periodic system or mixture thereof, such as, chromium sulfide,molybdenum sulfide, tungsten sulfide and the like; oxides and sulfidesof Group VIII of the Periodic Table or mixture thereof, such as, thesultides of iron, cobalt, nickel, palladium, platinum, rhodium, osmium,iridium; mixtures of the above oxides and suliides of the metals ofGroup VI lefthand column and Group VIII, such as, a mixture of nickelsulde and tungsten sulfide, cobalt sulfide and molybdenum sulfide,nickel sulfide and molybdenum sultide and the like. These metals can bedeposited on absorbent carriers such as alumina, silica-alumina,silicazirconia, among others. Preferred catalysts include thosecomprising at least one of the metals having atomic numbers 44, `45, 46,76, 77 and 78 deposited on a composite-like oxide of at least 2 of themet-als of Group IIA, IIB, IVA, and IVB of the Periodic Arrangement ofthe Elements particularly where such composite has an activity index inexcess of 25. Additional preferred catalysts include a suliided orunsulded 1 to 8 weight percent cobalt oxide and 3 to 20 weight percentmolybdenum trioxide on a silica-alumina or silica-zirconia basecontaining silica in amounts from about 5 to about 95 weight percent.

The catalyst after use in hydrocracking for a period of time such thatits activity is detrimentally affected is subjected to regeneration. Forsuch purpose, the spent catalyst is contacted with an oxygen-containingatmosphere at an elevated temperature suicient to burn carbonaceousdeposits from the catalysts. Conditions for regenerating thehydrocracking catalysts include a temperature -betweenf about 6007 F.and about 1000 F., a pressure of from? atmospheric to about 500 poundsper square inch, a totali gas flow rate of from about 1 to about 20volumes perf volume of catalyst and an oxygen concentration of from'about v0.1 percent to percent. The oxygen may be diluted with nitrogenor other inert gas.

Pure hydrogen can be used in this process. Hydrogen of low purityobtained 'by recycle or other hydrogenating process can be used, but itis recommended that the recycle hydrogen be subjected to a purificationprocess to remove some of the undesirable impurities such as water,sulfur compounds, and the like. The hydrogen can be circulated at a ratein the r-ange from about 1000 to about 10,000 s.c.f. per barrel ofhydrocarbon charge preferably in the range from about 2000 to about 5000s.c.f. per barrel of charge. It is essential, however, to obtain ahydrogen consumption of at least about 750 s.c.f. per barrel ofhydrocarbon charge.

To obtain the improved turbine oils of this invention, the hydrocrackedproduct of asphalt-containing petroleum hydrocarbon is separated so asto provide a fraction hav ing a viscosity at 210 F. in the range fromabout 40 t0 about 70 S.S.U. and -a flash point of about 390 F, to about450 F. These fractions which can be obtained by distillation of thehydrocracked product can lbe used in its entirety as the improvedturbine or several fractions can be blended to produce turbine oils inthe form of a light, medium, or heavy oil product. In the embodiment ofthe present invention wherein the turbine oil fraction is to be passedover an adsorbent material percolation bed, a volume ratio of oil toadsorbent material :of from about 0.1 to about 10 at a temperature offrom about 50 F. to about 500 F. is employed. Preferably, the turbineoil is -percolated at conditions wherein an oil to clay volume ratio offrom about 2 to about 5 at a temperature of from about 120 F. to about300 F. is employed.

To obtain the improved automatic transmission fluids base stocks of thisinvention, the hydrocracked product of asphalt-containing petroleumhydrocarbon is separated so as to provide a fraction hafving a viscosityat 210 F. in the range of about 40 to about 50 S.S.U., a flash-point ofabout 390 F. to about 425 F., and a viscosity index in excess of 115.These fractions which can be obtained by distillation of thehydrocracked product can be used in its entirety as the improvedautomatic transmission uid base stock or several fractions can beblended to produce automatic transmission uid base stocks to providesuitable properties required of said oil.

After separation of the lubricating oil or components thereof from thehydrocracked product, the desired oil may contain some wax products.Removal of wax, if present, is accomplished by any treatmentconventionally used for dewaxing oils to give a pour point below about20 F. specifically for turbine oils, preferably in the range from about20 to about 25 F. Since the automatic transmission uid base stocksrequire a low wax content, it is essential that these oils be dewaxed attemperatures to provide oils having pour points below about 10 F'.Dewaxing to obtain exceptionally low pour points is essential forautomatic transmission fluid base stocks so as to decrease the amount ofpour depressantviscosity index improvers which may be required toprovide an oil which can be used in extreme cold weather climateswithout solidifying. The deep dewaxing operation generally decreases theviscosity index of the base; oils 5 to 10 points and significantlydemonstrates the requirement of the untreated base oil to have a'viscosity index in excess of about 115. With this extreme dewaxingoperation, therefore, the dewaxed base oils having viscosity indexes inexcess of about can be obtained which decreases the amount of aviscosity-index improve;`

material necessary to obtain a high viscosity-index transmission iiuid.Typical of a satisfactory dewaxing process is the method wherein the oilis dissolved in a solvent, such as, propane; methyl ethyl ketone andtoluene; and the like, cooling and filtering. The dewaxing solvent canbe removed by distillation.

The automatic transmission fluid base stocks obtained from thehydrocracked hydrocarbon may contain undesirable properties, such as,sludge-producing components or undesirable color characteristics. Theseproperties can be improved, if desired, by percolating the automatictransmission iiuid base stock, or the like in the presence of clay usingconventional procedures.

The lubricating oils produced by the process of this invention can befurther improved by the addition of conventional additives. The degreeof improvement is equal to and in many cases greater than theimprovement obtained by the addition of such conventional additives toother lubricating oils. Examples of additives which may be incorporatedin the improved lubricating oils are the conventional and knownviscosity-index improvers such as iso-butylene polymers, methacrylatesand the like, detergents including those of the class of metalsulfonates, metal phenates, and metal naphthenates, and polymericdispersants such as polyethylene glycol substituted polymethacrylates,and the like. Additional additives which can be used includeantioxidants such as zinc dithiophosphates, alkylated phenols and thelike and known rust inhibitors, if desired, -such as those of the classof amine derived succinic anhydrides. Other additives known in the artmay be added to obtain additional desired effects.

Examples of additives which may be incorporated in the improvedautomatic transmission iiuid base stocks are the conventional and knownviscosity index improvers including those of the class of methacrylate,iso-butylene polymers and the like. Other additives which can beincluded in the automatic transmission fiuid base stocks include theconventional and known detergents of the class of metal sulfonates,metal phenates, and metal naphthenates and the like; antioxidants suchas zinc dithiophosphates, alkylated phenols and the like; rustinhibitors such as those of the class of amine derived succinicanhydrides; and pour depressants such as polymethacrylates. Otheradditives known in the art may be added to obtain additional desiredeffects.

The hydrocracking process of this invention can be carried out in anyequipment suitable for catalytic hydrocracking operations. The processmay be operated batch-wise. It is preferable, however, and generallymore feasible to operate continuously. Accordingly, the process can beadapted to operations using a fixed bed of catalyst. Also, the processcan be operated using a moving bed of catalyst wherein the hydrocarbonflow can be concurrent or countercurrent to the catalyst flow. A fluidtype of operation can also be employed.

`Important advantages are apparent in using the processes of thisinvention over the conventional acid treatment and/or solvent reningprocedures in producing lubricating oils. Of significant importance,higher yields are obtained in the process of this invention over theconventional refining procedures since the lubricating oil l fraction ofthe charge stock is hydrocracked and converts the undesirable materialinto acceptable products thereby utilizing the entire crude charge stockto produce the improved lubricating oil. The acid treating and solventrefining procedure removes the undesirable material from the chargestock thereby decreasing the yield of the resulting product. Not onlyare higher yields obtained in the process of this invention, butlubricating oils are produced which have improved characteristics ofmaintaining its resistance to chemical breakdown during use, the abilityto maintain its body and efliciency under hightemperatures (shearstability) and the ability to maintain its stability under oxidizingconditions among other advantages over the conventional lubricatingoils.

The properties of the charge stocks used in the hydrocracking processare listed in Table I.

Table l Mid-Continent propane Mid-Conti- Pan Fuller- Oharge Stockdeasphalted nent 10% ton 15% raffinate Residuum Residuum Gravity, API23. 8 12.8 17. 2

Vacuum Assay, F.:

IB P

Pour Point, F Viscosity, S.S.U. at 210 F.- Asphalt-Tar, Volume percent;

The catalysts utilized were prepared by separately impregnating cobaltoxide and` molybdenum oxide on a silica-alumina (CMAS) orsilica-zirconia (CMZS) base and sulfiding the catalyst composite. Theresulting catalysts possessed the following compositions and properties:

OMZS CMAS A lzOa, Weight percent; 74: 2 S102, weight percent. 78. 3 15.4 ZrO2, Weight percent 10. 6 M003, weight percent 8.5 8. 1 C00, weightpercent 2. 6 2. 3 Sulfur content, Weight percent 6. 7 3.8 Packeddensity, g./cc 0. 93 0. 98 Surface area, m.2,/g. 373 241 Pore volume,ec./g 0.27 0.38 Average pore diameter, A 29 64 The propane deasphaltedMid-Continent raffinate, the Mid-Continent 10% residuum and the PanFullerton 15% residuum were hydrocracked over the CMAS catalystdescribed above, using the .following conditions:

Hydrocracking conditions:

Pressure, p.s.i.g 3, 000 3, 000 3, 000 Temperature, F 779 820 800 Liquidhourly space velocity. 0. 2 0. 2 0. 2 H2 O1rc..s.c.f./b 10, 000 10, 00010, 000 Conversion, percent Volume 46 70 48 The hydrocracked productswere distilled to separate from the total liquid product, fractionssuitable for turbine oils having the properties described in Table IIbelow.

An oxidation stability test was conducted on each of the hereinafterdescribed turbine oil fractions. This test involved subjecting a 25milliliter sample of the oil to l5 liters of air per hour for 40 hoursin the presence of 15.6 square inches of iron wire, 0.78 square inch ofcopper wire, 0.87 square inch of aluminum wire and 0.167 square inch oflead surface. The temperature was maintained at 260 F. Results are givenin Table II.

Table Il PROPERTIES OF TURBINE OIL FRACTIONS Deasplialted Mid-Conti- PanFuller- Initial Viscosity Mid-Continent nent 10% ton 15% ResiduumRcsiduum S.S.U. at 210 F 41.2 53.2 41.0 52.1 Kineniatie viscosity at F4. 55 8. 21 4. 50 7. 00 Viscosity Index 130 121 116 104 Neutralizationnumber 111g. KOH/gm 0.06 0.08 0. 05 0.1

OXIDIZED OIL TEST Kinematie viscosity at 210 F 17. 44 32. 42 4. 79 8. 40Kinematic viscosity increase, percent 283 205 6. 7. 47 Neutralizationnumber mg. KOH/gm 18.1 16.1 1. 5 1. 5 Lead Loss, mg 155. 3 214. 4 0. 80. 9

The small changes in neutralization number and viscosity and. the lowlead loss of the fractions obtained from the asphalt-containinghydrocarbons demonstrates the superior oxidation stability of theseturbine oils over those fractions of the deasphalted hydrocarbons. Thisadvantage aids in eliminating or reducing antioxidant additives requiredof a turbine oil. The above comparison also shows the improvedcharacteristics of the hydrocracked turbine oils obtained from theasphalt-containing hydrocarbons in that these oils maintained their lowviscosity during use and significantly suppressed acid formation overthe hydrocracked turbine oils obtained from the deasphalted residuum. Asshould be realized, the turbine oil fractions obtained from thehydrocracked asphalt-containing petroleum hydrocarbons are suitable foruse as lubricating oils to which lubricating oil additives can be addedif desired.

EXAMPLE 2 The turbine oils of this invention can be further improved. bythe addition of conventional or known turbine oil additives. Thefollowing hydrocarbon charge stocks The hydrocracked products weredistilled and dewaxed and a light turbine oil fraction from eachhydrocarbon charge stock was obtained having the following properties:

For comparison purposes, a light turbine oil was obtained directly bythe conventional refining of an East Texas Crude. This turbine oilwithout the benefit of hydrocracking had the following properties:

Gravity, API 32.1 Pour point, F, 20 Flash, F 395 S.S.U. 100 F 153 S.S.U.210 F 43.5 VI 102 Neutralization number, mg. KOH/ g. 0.03

Each of the above-described turbine oil base stocks were mixed withconventional turbine oil additives in the following formulation:

Weight percent Turbine oil base stock 99 6l 2,6-ditertiary butylparacresol 0.25 Zinc dihexyl dithiophosphate 0.10 Oleic acid-triethylenetetramine-tetrapropenyl succinic anhydride reaction product 0.04

Each of the above-described formulations were subjected to a Test ForOxidation of Inhibited Steam Turbine Oils as described in the ASTMManual under Specifica- ,ton No. D943-54. The following results of TableIII were obtained.

Table III [Time of test-hours] l 270 l 6009 1,000 1,450 l 1,790 l 3,5001 5,000 5,700

Hydroeracked Turbine Oil ob- Neutralization number, 0.17 0.19 0. 20 2. 02. 0 2. 0 2. 0 2. 0

tained from a deasphalted mg. of KOH/g.

residuum. Hydrocracked Turbine Oil obd0 0.25 0.30 0.38 0.40 0.40 0.700.90 2.0

tained from an asphalt-containing residuum. Conventional Turbine Oil(not do 0.10 0.10 0.10 0.10 2. 0 2. 0 2. 0 2.0

hydrocracked).

were hydrocracked utilizing the hydrocracking conditions as describedbelow using the CMZS catalyst described in Example 1.

1 At 67 percent. 2 At 56 percent.

The results of `the turbine oil stability test are plotted in theaccompanying ligure wherein the time of the test is plotted vs. theneutralization number, mg. KOH/g. of the formulated turbine oil. Forturbine oils, the absolute -tolerability of acidity is reached when theneutralization number reaches 2. The figure significantly demonstratesthat the formulation of the turbine oil obtained from anasphalt-containing hydrocarbon is approximately 3 to 4 times morestable, i.e., for the formation of tolerable acid, than the turbine oilobtained from the hydrocracked deasphalted residuum and the turbine oilobtained directly from a typical crude oil. The improved formulations ofthis invention provide for a more stable turbine oil which maintains thedesired property characteristics over an extended life period.

EXAMPLE 3 A portion of a 25% Mid-Continent residuum charge stock havingthe properties as described in Example 2 was hydrocraeked over asullided catalyst composed of cobalt oxide and molybdenum oxide on asilica-zirconia base (properties described in Example 1) utilizing thefollowing hydrocracking conditions:

Reaction temperature for 45% conversion, F 778. Pressure pounds persquare inch gauge 3000. Liquid hourly space velocity (fresh feed) 0.2.Hydrogen circulation ratio, s.c.f. per

barrel of fresh feed 10,000. Operation Single pass (oncethrough)Reaction temperature for 45% conversion, F. 790 Pressure, pounds persquare inch gauge 3000 Liquid hourly space velocity (fresh feed) 0.2Hydrogen circulation ratio, s.c.f. per barrel of fresh feed 10,000Operation Liquid recycle The following comparative results of the singlepass and recycle operations were obtained as described in Table IVbelow:

.1.0 EXAMPLE 4 An automatic transmission iluid base stock was obtainedby hydrocracking a portion of a 25% Mid-Continent residuum (propertiesdescribed in Example 2) over a sulded catalyst composed of cobalt oxideand molybdenum oxide on a silica-zirconia base (preparation andproperties described in Example 2) at a temperature of 782 F., aconversion level of 51 volume percent (100- material in the productboiling above 650 F. expressed as volume percent of charge) a pressureof 3000 pounds per square inch gauge, a liquid hourly space velocity of0.2, and a hydrogen circulation ratio of 10,000 s.c.f. per barrel ofcharge. The resulting hydrocracked product was distilled to obtain afraction having a viscosity at 210 F. of 42 S.S.U. This fraction wasdewaxcd at 35 F. to obtain a pour point of 15 F. and viscosity index of115. This fraction demonstrates the same resistance to the oxidationreactions as the hydrocracked turbine oil in Example 1.

A conventional automatic transmission fluid base stock was prepared byblending a solvent refined paraffinic neutral oil designated as A, and aIsolvent refined coastal distillate oil designated as B. These oils havethe folvolume.

Catalyst aging rate, F. per day Viscosity of 650 F plus oil products at45% conv.

S.S.U. at 210 F.

Viscosity Index F. 650 F. plus oil products having a viscosity at 210I". of 42 S.S.U. and dewaxed to a pour point of 20 F.

Very lowl.- Very low.l 63.7 51.5.

1 Utilizing similar conditions as the single pass operation, thecatalyst aging rate was so low that a number could not be determined andassigned.

The use of a recycle stock boiling below lubricating oil stocks (400 to700 F.) in the hydrocracking operation significantly improves thecatalyst aging rate over the rate of the single pass operation. Thisrecycle operation will extend catalyst life and periods of operationbefore regeneration is necessary over the single pass operation. Inaddition to the improved catalyst aging characteristics, the recycleoperation utilizing the hydrocracked product boiling in the range ofabout 400 F.- 700" F. provides a higher viscosity of the lubricating oilproducts boiling above 650 F. and higher viscosity indices of aparticular oil fraction than the single pass operation and the recycleoperation utilizing a heavy hydrocracked cycle stock boiling in excessof 850 F. These results indicate that a specific hydrocracked cyclestock (400700 F.) can be used to obtain additional advantages ofextended catalyst life and improved product characteristics.

The following automatic transmission fluids were prepared by theformulation of the above-described stocks and additives:

Conventional I-Iydrocracked PROPERTIES OF THE AUTOMATIC TRANSMISSIONFLUIDS As is demonstrated in the above example, .the hydrocrackedautomatic transmission lluid formulation using@y conventional additivesis a less viscous oil at lower tem- 2 peratures and has a higherviscosity index than a conventional automatic transmission uid using theequivalent amounts of the same additives (see S.S.U. viscosities at 100F. and 0 F.). The comparative data of they Brookfield viscosities at F.and-30 F. indicates that 2 the viscosity of the hydrocrackedtransmission uid ranges from about 1.7 to 2 times less viscous than theconventional transmission fluid. Other physical properties of thehydrocracked transmission fluid are as good or betf,l ter than theconventional transmission iiuid. Obtaining a low viscositly at lowtemperatures is a specific requirement necessary of a Itransmission uidwhen used for lubrication in extremely cold climates and avoidingsoldiiication of said fluid. i

EXAMPLE The catalyst utilized in the hydrocracking process was prepared.by separately impregnating cobalt oxide and 4 molybdenum oxide onsilica zirconia 4and suliding the catalyst composite. This catalyst willbe designated as CMZS. The resulting catalyst possessed the followingcomposition and properties:

CMZS A1203, weight percent SiO2, weight percent 78.3 ZrO2, weightpercent 10.6 M003, weight percent 8.5 CoO, weight percent 2.6 Sulfurcontent, weight percent 6.7 Packed densiyt, g./cc. 0.93 Surface area,m.2/ g. 373 Pore volume, cc./g. 0.27 Average pore diameter, A. 29

The following hydrocarbon charge stocks were hydrocracked utilizing thehydrocracking conditions as described below using the CMZS catalystdescribed above.

Mid-Continent 25% Rcsiduum Deasphalted Kuwait Residuum A B 1Hydrocracking Conditions:

Pressure, psig 3, 000 3,000 3, 000 Temperature, F. 794 750 SpaceVelocity 0. 2 Hg Circ.l s.c.f./b 10, 000 Conversion, Percent Volume. 5042 1 At 67%. 2 At 56%.

The hydrocracked products were distilled and dewaxed and a light turbineoil fraction from each hydrocarbon charge stock was obtained having thefollowing properties:

Mid-Continent 25% Residuum Deasphalted Kuwait Residuum A B Oil Gravity,API 29. 8 30 35.9 Viscosity:

S.S U. at 210 42. 0 43.1 42.8 KinematicVisocity at 210 F., C.S 4. 81 5.14 5.05 Viscosity Index 105 11G 126 Pour Point, F 20 20 20 Gravity, API32.1

Pour point, F. 20 Flash, F. 395 S.S.U. F. 153

S.S.U. 210 F. 43.5

Neutralization number, mq. KOH/ g 0.03

Each of the above-described turbine oil base stocks were mixed withconventional turbine oil additives in the following formulation Weightpercent Tur-bine oil base stock 99.61

2,6-ditertiary butyl paracresol 0.25 Zinc dihexyl dithiophosphate 0.10Oleic acid-triethylene tetramine-tetrapropenyl succinic anhydridereaction product 0.04

Each of the above-described formulations were subjected to a Test forOxidation of Inhibited Steam Turbine Oils as described in the ASTMManual under Specification No. D943-54. The following results of Table lwere obtained.

Table V [Time of test-hours] Hydrocraeked Turbine Oil Neutralizationnumber, 0.17 0.19 0. 2. 0 2. 0 2. 0 2. 0 2. 0 2. 0 2. 0 2. 0

obtained from a deasphalted mg. of KOH/g. n residuum. HydrocrackedTurbine Oil .do 0. 0.30 0.38 0. 40 0. 46 0.70 0. 90 2. 0 2. 0 2. 0 2. 0

obtained from an asphaltcontaining residuurn. Hydrocracked Turbine Oildo 0 0 0 0 0. 05 0.25 0.43 0.51 0. 57 1.05 2. 0

obtained from an asphaltcontaining residuum with Percolation treatment.Conventional Turbine Oil (not do 0.10 0.10 0.10 0.10 2. 0 2. 0 2. 0 2. 02. 0 2. 0 2. 0

hydrocracked).

The results of the turbine oil stability test are plotted in theaccompanying gure wherein the time of the test is plotted vs. theneutralization number, mg. KOH/g. of the formulated turbine oil. Forturbine oils, the absolute tolerability of acidity is reached when theneutralization number reaches 2. The figure significantly demonstratesthat the formulation of the turbine oil obtained from the hydrocrackingof an asphalt-containing hydrocarbon followed by percolation can be used1900 hours longer than the unpercolated hydrocracked turbine oilobtained from an asphalt-containing hydrocarbon for the formation oftolerable acid in the test turbine oil. The figure further demonstratesthat the formulation of the percolated turbine oil obtained byhydrocracking an asphalt-containing hydrocarbon is approximately 4 to 8times more stable, i.e. Afor the formation of tolerable acid, than theturbine oil obtained from the hydrocracked reasphalted residuum and theturbine oil obtained directly from a typical crude oil. The improvedformulations of this invention provide for a more stable turbine oilwhich maintains the desired property characteristics over an extendedlife period.

An additional advantage observed in the test for Oxidation of InhibitedSteam Turbine Oil relates to the formation of sludge in minor amounts at300 hours for the unpercolated hydrocracked turbine oil obtained fromthe asphalt-containing hydrocarbon, whereas no evidence of sludge wasobserved in the percolated hydrocracked turbine oil obtained from theasphalt-containing hydrocarbon until after 2100 hours of the oxidationtest.

It is to be understood that the foregoing description is merelyillustrative of preferred embodiments of the invention of which manyvariations may be made by those skilled in the art within the scope ofthe following claims without departing from the spirit thereof.

We claim:

1. A process for producing an improved turbine oil which comprisescontacting a petroleum hydrocarbon fraction boiling above about 650 F.and containing about 2 to about 70 volume percent asphalt with acatalyst having hydrogenation and cracking properties in the presence ofhydrogen at pressures in the range from about 1700 pounds per squareinch gauge to about 4000 pounds per square inch gauge, at temperaturesin the range from about 700 to about 870 F., a hydrogen circulation ratein the range from about 1000 to about 10,000 s.c.f. per barrel ofcharge, and a liquid hourly space velocity from about 0.1 to about 2.0to obtain a hydrocracked hydrocarbon oil and separating from saidhydrocracked hydrocarbon oil an improved turbine oil having a viscosityat 210 F. in the range from about 40 to about 70 S.S.U. and a flashpoint in the range from about 390 F. to about 450 F.

2. A process for producing improved automatic transmission uid basestock which comprises contacting a petroleum hydrocarbon fractionboiling above about 650 F. and containing about 2 to about 50 volumepercent asphalt with a catalyst having hydrogenation and crackingproperties in the presence of hydrogen at pressures in the range fromabout 1700 pounds per square inch gauge to about 4000 pounds per squareinch gauge, at temperatures in the range from about 700 to about 870 F.,a hydrogen circulation rate in the range from about 1000 to about 10,000s.c.f. per barrel of charge and a liquid hourly space velocity fromabout 0.1 to about 2.0 to obtain a hydrocracked hydrocarbon oil andseparating from said hydrocracked hydrocarbon oil an improved automatictransmission fluid base stock having a viscosity at 210 F. in the rangefrom about 40 to about 50 S.S.U., a Hash point of about 390 F. to about425 F. and a viscosity index in excess of about 115 and dewaxing saidbase stock to a pour point of -10 F. or less.

3. A process for producing improved lubricating oils which comprisescontacting a petroleum hydrocarbon fraction boiling above about 650 F.and containing about 2 to about 70 volume percent asphalt with acatalyst having hydrogenation and cracking properties in the presence ofhydrogen at pressures in the range from about 1700 pounds per squareinch gauge to about 4000 pounds per square inch gauge, at temperaturesin the range from about 700 F. to about 870 F., a hydrogen circulation vfraction boiling above 650 F. and containing about 2 to about 70 volumepercent asphalt with a catalyst having hydrogenation Vand crackingproperties in the presence of hydrogen at pressures in the range fromabout 2000 pounds per square inch gauge to about 3500 pounds per squareinch gauge, at temperatures in the range from about 700 F. to about 870F., a hydrogen circulation rate in the range from about 1000 to about10,000 s.c.f. per barrel of charge and a liquid hourly space velocityfrom about 0.1 to about 2.0 to obtain a hydrocracked hydrocarbon oil andseparating from said hydrocracked hydrocarbon oil an improved turbineoil having a viscosity at 210 F. in the range from about 40 to about 70S.S.U. 21513 .a1-flash point in the range from about 390 F. to about 5.A process for producing an improved lubricating oil which comprisescontacting a petroleum hydrocarbon fraction boiling above about 650 F.and containing from about 2 to about 70 volume percent asphalt with arecycle stock boiling in the range from about 400 F. to about 700 F.obtained from hydrocracking said asphalt-containing petroleumhydrocarbon fraction, in which the volumetric ratio of said recyclestock to said fraction ranges from about 0.121., respectively to about10:1 respectively, with a sulfided catalyst composed of cobalt oxide andmolybdenum oxide on a silica-zirconia base in the presence of hydrogenat pressures in the range from about 1700 pounds per square inch gaugeto about 4000 pounds per square inch gauge at temperatures in the rangefrom about 700 F. to about 870 F., a hydrogen circulation rate in therange from about 1000 to about 10,000 s.c.f. per barrel of charge, and aliquid hourly space velocity from about 0.1 to about 2.0 to obtain ahydrocracked hydrocarbon oil and separating from said hydrocrackedhydrocarbon oil an improved lubricating oil having a viscosity at 210 F.in the range from about 35 to about 125 S.S.U. and a Hash point in therange from about 310 F. to about 510 F.

6. A process for producing an improved turbine oil which comprisescontacting a petroleum hydrocarbon fraction boiling above about 650 F.and containing about 2 to about 70 volume percent asphalt with a recyclestock boiling in the range from about 400 F. to about 700 F. obtainedfrom hydrocracking said asphalt-containing petroleum hydrocarbonfraction, in which the volumetric ratio of said recycle stock to saidfraction ranges from about 1:1 respectively, to about 5:1 respectively,with a sulded catalyst composed of cobalt oxide and molybdenum oxide ona silica-alumina base in the presence of hydrogen at pressures in therange from about 1700 pounds per square inch gauge to about 4000 poundsper square inch gauge, at temperatures in the range from about 700 toabout 870 F., a hydrogen circulation rate in the range from about 1000to about 10,000 s.c.f. per barrel of charge, and a liquid hourly spacevelocity from about 0.1 to about 2.0 to obtain a hydrocrackedhydrocarbon oil and separating from said hydrocracked hydrocarbon oil animproved turbine oil having a viscosity at 210 F. in the range fromabout 40 to about 70 S.S.U. and a ash point in the range from about 390F. to about 450 F.

7. A process for producing improved automatic transmission uid basestock which comprises contacting a petroleum lhydrocarbon fractionboiling above about 650 F. and containing about 2 to about 50 volumepercent asphalt with a recycle stock boiling in the range from about 400F. to about 700 F. obtained from hydrocracking said -asphalt-containingpetroleum hydrocarbon fraction, in which the volumetric ratio of saidrecycle stock to said fraction ranges from 1:1 respectively, to about :1respectively, with a catalyst having hydrogenation and crackingproperties in the presence of hydrogen at pressures in the range fromabout 1700 pounds per square inch gauge to about 4000 pounds per squareinch gauge, a hydrogen circulation rate in the range from about 1000 toabout 10,000 s.c.f. per 'barrel of charge and a liquid hourly spacevelocity from about 0.1 to about 2.0 to obtain a hydrocrackedhydrocarbon oil and separating from said hydrocracked hydrocarbon oil animproved automatic transmission fluid base stock having -a viscosity at210 F. in the range from about 40 to about 50 S.S.U., a ash point ofabout 390 F. to about 425 F. and a viscosity index in excess of about115 and dewaxing said base stock to a pour point of 'F. or less.

8. A process for producing an improved lubricating oil which comprisescontacting -a petroleum hydrocarbon fraction boiling above about 650 F.and containing about 2 to about 70 volume percent asphalt with a recyclestock boiling in the range from about 400 F. to about 700 F. obtainedfrom hydrocracking said asphalt- [containing petroleum hydrocarbonfraction, in which the volumetric ratio of said fraction ranges fromabout 1:1 respectively, to about 5 :1 respectively, with a catalysthaving hydrogenation and cracking properties in the presence of hydrogenat pressures in the range from about 1700 pounds per square inch gaugeto about 4000 pounds per square inch gauge at temperatures in the rangefrom about 725 F. to about 850 F., a hydrogen circulation rate in therange from about 1000 to about 10,000 s.c.f. per barrel of charge, and aliquid hourly space velocity from about 0.1 to about 2.0 to obtain ahydrocracked hydrocarbon Oil ,and separating from said hydrocrackedhydrocarbon oil an improved lubricating oil having a viscosity at 210 F.in the range from about 35 to about S.S.U. and a ash point in the rangefrom about 310 F. to about 510 F.

9. A process for producing an improved turbine oil which comprisescontacting a petroleum hydrocarbon fraction boiling above about 650 F.and containing about 2 to about 70 volume percent asphalt with a recyclestock boiling in the range from about 400 F. to about 700 F. obtainedfrom hydrocracking said asphaltcontaining yhydrocarbon fraction, inwhich the volumetric ratio of said recycle stock to said fraction rangesfrom about 1:1 respectively, to about 5:1 respectively, with a catalysthaving hydrogenation and cracking properties in the presence of hydrogenat pressures in the range from about 2000 pounds per square inch gaugeto about 3500 pounds per square inch gauge, at temperatures in the rangefrom about 700 F. to about 870 F., a hydrogen circulation rate in therange from about 1000 to about 10,000 s.c.f. per barrel of charge, and aliquid hourly space velocity from about 0.1 to about 2.0 to -obtain ahydrocracked Ahydrocarbon oil and separating from said hydrocrackedhydrocarbon oil an improved lubricating oil having a viscosity at 210 F.in the range from about 40 to about 70 S.S.U. and a ash point in therange from about 390 F. to about 450 F.

10. A process for producing an improved lubricating oil which comprisescontacting an asphalt-containing petroleum hydrocarbon fraction boilingabove about 650 F. and containing from about 2 to about 70 volumepercent asphalt with a recycle stock boiling in the range from about 400F. to about 700 F. obtained from hydrocracking said asphalt-containingpetroleum hydrocarbon fraction, in which the volumetric ratio of saidrecycle stock to said fraction ranges from about 1:1 respectively, toabout 5 :1 respectively, with a catalyst having hydrogenation andcracking properties in the presence of hydrogen at pressures in therange from about 1700 pounds per square inch gauge to about 4000 poundsper square inch gauge, at temperatures in the range from about 700 toabout 870 F., a hydrogen circulation rate in the range from about 1000to about 10,000 s.c.f. per barrel of charge, and a liquid hourly spacevelocity from about 0.1 to about 2.0 to obtain -a hydrocarckedhydrocarbon oil and separating from said hydrocracked hydrocarbon oil animproved turbine oil having a viscosity at 210 F. in the range fromabout 40 to about 70 S.S.U. and a tlasb point in the range from about390 F. to about 450 F.

11. The process of claim 3 wherein the hydrocracking temperature iswithin the range of 725 F. to 850 F. and at least one lubricating oiladditive is added to the lubricating oil product.

12. The process of claim 1 wherein the turbine oil product is percolatedthrough a bed of suitable adsorbent material employing a volume ratio ofturbine oil to adsorbent material from about 0.1 to about l0 at atemperature in the range from about 50 F. to about 500 F.

13. The process of claim 12 wherein the absorbent is activated clay.

14. The process of claim 4 wherein the turbine oil product is percolatedthrough a bed of suitable adsorbent material employing a volume ratio ofturbine oil to adsorbent material from about 0.1 to about 10 at atemperature in the range from about 50 F. to about 500 F.

15. The process of claim 14 wherein the adsorbent is activated clay.

16. A process for producing an improved turbine oil which comprisescontacting a petroleum hydrocarbon fraction boiling above about 650 F.and containing about 2 to about 70 volume percent asphalt with acatalyst having hydrogenation and cracking properties in the presence ofhydrogen at pressures in 4the range from about 2000 pounds per squareinch gauge to about 3500 pounds per square inch gauge, at temperaturesin the range from about 725 F. to about 850 F., a hydrogen circulationrate in the range fro-m about 1000 to about 10,000 s.c.f. per barrel ofcharge, and a liquid hourly space velocity from about 0.1 to about 2.0to obtain a hydrocracked hydrocarbon oil; separating from saidhydrocracked hydrocarbon oil a turbine oil having a viscosity at 210 F.in the range fro-m about 40 to -about 70 S.S.U. and a flash point in therange from about 390 F. to about 450 F.; and percolating said turbineoil product through a bed of suitable adsorbent material employing avolume ratio `of turbine oil to adsorbent material from about 0.1 toabout at a temperature in the range from about 50 F. to about 500 F.

17. The process of claim 16 wherein the adsorbent is activated clay.

18. A process for producing an improved turbine oil which 4comprisescontacting a petroleum hydrocarbon fraction boiling above about 65 0 F.and containing about 2 to about 70 volume percent asphalt with a suldedcatalyst composed of cobalt and molybdenum oxide on a silica-zirconiabase in the presence of hydrogen at pressures in the range from about2000 pounds per square inch gauge to about 3500 pounds per square inchgauge, at temperatures in the range from about 725 F. to about 850 F., ahydrogen circulation rate in the range from about 1000 to about 10,000s.c.f. per barrel of charge, and a liquid hourly space velocity fromabout 0.1 to about 2.0 to obtain a hydrocracked hydrocarbon oil;separating from said hydrocracked hydrocarbon oil a -turbine oil havinga Visco-sity at 210 F. in the range from about 390 F. to about 450 F.;and percolating said turbine oil product through a bed of suitableadsorbent material employing a volume ratio of turbine oil to adsorbentmaterial from about 0.1 to about 10 at a temerature in the range fromabout F. to about 500 F.

19. The proces-s of claim 18 wherein the adsorbent is yactivated clay.

20. A process for producing an improved turbine oil which comprisescatalytically hydrocracking la petroleum Ihydrocarbon fraction boilingabove about 650 F. and containing about 2 to about 70 volume percentasphalt under conditions sufficient to limit conversion to hydrocarbonproducts boiling below about 650 F. within the range of from about 25%to about 45% and produce hydrocracked products boiling above 650 F.;separating from said hydrocracked products a turbine oil having aviscosity at 210 F. in the range of from about 40 to about S.S.U. and afla-sh point in the range of from about 390 F. to about 450 F.;percolating said turbine oil product through a bed of adsorbent claytype m-aterial employing a volume ratio of turbine oil to adsorbentmaterial of from about 0.1 t-o about l10` and adding suitable additivesto the turbine oil recovered from said percolation step.

21. The process of claim 4 wherein a hydrocracking temperature of 725 to850 F. is employed and an additive is added to the turbine oil.

References Cited by the Examiner UNITED STATES PATENTS 3,142,6357/1964-` Coonradt 208-111 DEL'BERT E. GANTZ, Primary Examiner.

8. A PROCESS FOR PRODUCING AN IMPROVED LUBRICATING OIL WHICH COMPRISESCONTACTING A PETROLEUM HYDROCARBON FRACTION BOILING ABOVE ABOUT 650*F.AND CONTAINING ABOUT 2 TO ABOUT 70 VOLUME PERCENT ASPHALT WITH A RECYCLESTOCK BOILING IN THE RANGE FROM ABOUT 400*F. TO ABOUT 700*F. OBTAINEDFROM HYDROCRACKING SAID ASPHALTCONTAINING PETROLEUM HYDROCARBONFRACTION, IN WHICH THE VOLUMETRIC RATIO OF SAID FRACTION RANGES FROMABOUT 1:1 RESPECTIVELY, TO ABOUT 5:1 RESPECTIVELY, WITH A CATALYSTHAVING HYDROGENATION AND CRACKING PROPERTIES IN THE PRESENCE OF HYDROGENAT PRESSURES IN THE RANGE FROM ABOUT 1700 POUNDS PER SQUARE INCH GAUGETO ABOUT 4000 POUNSD PER SQUARE INCH GAUGE AT TEMPERATURES IN THE RANGEFROM ABOUT 725*F. TO ABOUT 850*F., A HYDROGEN CIRCULATION RATE IN THERANGE FROM ABOUT 1000 TO ABOUT 10,000 S.C.F. PER BARREL OF CHARGE, AND ALIQUID HOURLY SPACED VELOCITY FROM ABOUT 0.1 TO ABOUT 2.0 TO OBTAIN AHYDROCRACKED HYDROCARBON OIL AND SEPARATING FROM SAID HYDROCARCKEDHYDROCARBON OIL AN IMPROVED LUBRICATING OIL HAVING A VISCOSITY AT 210*F.IN THE RANGE FROM ABOUT 35 TO ABOUT 125 S.S.U. AND A FLASH POINT IN THERANGE FROM ABOUT 310*F. TO ABOUT 510*F.